Diffusion Coatings with the Participation of Titanium, Aluminium and Silicon on Surface of the Steel 12X18H10T

Abstract

Patterns of forming a multilayered diffusion coatings after complex saturation of titanium, aluminum and silicon to steel to improve heat resistance 12Cr18Ni10Ti were obtained and studied. The possibility of obtaining titanium-aluminum-silicon layers on steel 12Cr18Ni10Ti powder in containers with a gate in unpressurized conditions at temperature 1050 °C and with duration 4 hours was studied. As initial components powders of titanium, aluminum, silicon, aluminum oxide, ammonium chloride were used. The phase and chemical composition, structure and micro-hardness of the obtained coatings were investigated. For titanation and titanium-calorizing, coating phase composition consists of compounds zone Ti 4 Fe 2 O, Fe 2 Ti, TiS, the transition zone and for titanium-aluminum-silicon: Ti 3 (Al,Fe), (Fe,Al,Ni) 2 Ti, (Fe,Al,Ni)Ti, Ti(C,N,O) and the transition zone. In titanium-aluminum-silicon content in the coating zone Fe 2 Ti compounds in the layer is 1,5 % by weight, and in the transition zone at the boundary with the zone of connection – 1,2 % by weight. During oxidation of obtained coatings, degradation carries out in phase composition and structure. Heat-resistance of steel 12Cr18Ni10Ti with titanium aluminum siliconized coating increases 4,0 times in comparison with steel without coating.